Hi @dafex36959_6595,
Based on the exceptions, this is most likely due to an invalid character in the display name field or in an associated group. This is due to a bug that is buried in a third-party library that is based on another library that is based on an some RFC standard.... but who knows. It's been a known issue for years, and presumably end-users of this library (it's the #1 library for LDAP on .NET) have simply worked-around the issue by not using those characters in domains, groups, etc. I'm afraid it's just not something we are able to fix.
We really hate giving this response, but we also cannot go down the rabbit hole of trying to fix the library to support this edge case -- Unfortunately, this is a "limitation" of our software and recommend working around the issue by either removing the unescapable character (typically a '# or a ',') or try using ADv4 and override the display name to use a different field and/or group discovery.
Thanks,
Dan